Steam generation in two stages



I May 4 1926.

Filed August '3, 1922 vwemtoz Patented May 4, 1926.

UNITED STATES PATENT OFFICE.-

EMIL JOSS E, OF BERLIN, GERMANY, ASSIGNOB T0 AKTIEBO-LAGETVAPORAOKUMULA- TOR, OF STOCKHOLM, SWEDEN} A CORPORATION.

STEAM GENERATION IN TWO STAGES.

To all whom it mag concern:

Be it known that I, EMIL J ossn, a sub ect of Germany, residingatBerlin, Germany, have invented certain new and useful Improvements inSteam Generation in Two Stages, of which the following is aspecification.

' My invention relates to steam plants and more particularly to plants.equipped Wlth' steam accumulators in which steam is stored at times whenthere is a surplus of steam generation over steam consumption and fromwhich steam is delivered into the steam lines of the plant for purposesof low pressure steam consumption at times'when the demand for steamexceeds the steam generation; Y

My invention has for its primary object to generate steam in two stagesand in the referred embodiment-this is accom lished y generating highpressure steam or use in the plant in a boiler of ordinary type andgenerating lowpressure steam in a separate container which constitutesan accumulator. A further object of my invention is to obtain a betterutilization of the heating surfaces and the flue ases than has hitherto.

been possible. This is accomplished by the arrangement of a feed-heater, preferably heated by flue gases, an accumulator, and a primaryboiler in a novel way as hereinafter set out.

apparent as the description proceeds.

The accompanying drawing shows-more or less diagrammatically, one formof my invention.

Referring to the drawing 1 designates the primar steam generator whichmay constitute aboiler of any known type. In this primary steamgenerator h gh presseure steam is generated for use in high pressuresteam consumers of any kind, the

high pressure-section H .of a turbine being shown byway; ofillustration, 2 1s a fluegas feed water'preheater which is so amplydimensioned that the feed water will be pre-' heated to a hightemperature, for example,

300 F. at a normal load. Feed water is forced into the preheater 2 bymeans of the pump 4, and conduits ,6 and 7. The water passing into thepreheater, as is customary in steam lants,jhas a temperature ofapproximate y 100 to 120 F. The pump 4 forces the feed water through thecondult 7 and through the tubes of the preheater 2 in countercurrent tothe flow of flue" gases through the waste heat flue 22. The feed wateron leaving the preheater passes through conduit 8. From this conduit/thefeed water flows into the accumulator 3.

The accumulator 3 is, in effect, an auxiliary steam generator for lowpressure steam in which there is a partial generation of steam by meansof a drop in pressure. At the lower pressure, the heat 'of'liquidcontained in the feed water is less- The difference in heat contentofthe liquid between the respective ressures is used to cause anevaporation o a partof the feed water.

The low pressure, steam thus generated in the accumulator by flash isused in the low pressure consumers of the plant. A second boiler feedpump 5 draws water from the accumulator 3 and forces the same throughthe'conduit 10 to the primary generator.

If desired a valve 16 may be inserted in conduit 8, the said valveoperatingto' maintain the pressure in the preheater constant preferablyat the maximum value of the steam pressure in the accumulator, so thatthe pressure in the preheater is not subject to variations in thepressure of the accumu- I labor. I have shown, in the drawings forpurposes of explanation, one form of valve which will perform thefunction ascribed to it but it is to be understood that any type ofvalve which will perform this function may be used. By means of valve 16the feed .water delivered to the accumulator from preheater 2 containsmore heat of liquid than if the pressure in the preheater is the same asand varies with the pressure in the accumulator, thus allowing a greatersteam generation byflash in the accumulator. Furthermore'valve 16constitutes a protection against boiling and evaporation inthepreheater. 2, allowing a higher water temperature in-the preheater.\Vhen the valve 16 is not used, the pressure of the preheater is thesame as the pressure in the auxiliary generator and varies therewith.

The accumulator 3 supplies low" pressure steam by means of the conduits13 and 23 to the low pressure consumers of the plant. This steam may beused for heating purposes as indicated at R or for generation of powerin theintermediate stages of a steam engine or steam turbine, asindicated at M. It is obvious that the steam -drawn off sure. 1

through conduit 13, may be used in any consumers using steam ofrelatively'low pres- ;higher than the pressure in the auxiliarygenerator 3, thus allowing a higher temperature of water in thepreheater 17 To take'care of surplus steam generation in the primarygenerator '1 a conduit 12 connects the steam dome of the primarygenervator with the water space of the accumulater, and in this'c-onduitis inserted a valve 11, the operation of which is similar'to that ofthevalve 16. This valve 11 is set to open at a somewhat lowerpressurethan the safety valve 24 on the boiler 1, and when the pressure in theboiler exceeds the'pressure 'at which the valve 11 opens, the excess ofsteam generated is admitted into the water space of the accumulatorwhereb the water contained in the. accumulator is heated and thepressure therein is raised, so that this heat stored can be withdrawn atsome other 1 time in the form of low pressure steam,

by dropof pressure.

When the quantity of water delivered by reheater 2 is greater than thedemand for eed water in'the primary boiler the auxiliary generator 3constitutes a feed water accumulator; when there is a greater absorptionofheat in preheater 2 than there is a demand for lowpressuresteam, theauxiliary generator 3 constitutes a heat accumulator:

when there is a surplus of steam generation in the primar generator, andthe excess steam is store in the auxiliary generator 3, it constitutes asteam accumulator.

vIn order to avoid heat losses due to radiation the accumulator may beinsulated by non-conducting material indicated at 25.

While I have. shown .and described one form of my invention I wish itunderstood that the inventionis not-limited tothe pre cise emobdimentset forth but, may be modified within the scope of the appended, claims.What I claim as new and desire to secure byLetters Patent of the UnitedStates of America is: Y

1. In a steam plant, means to generate tween said preheater and saidboiler, in which container a drop in pressure is utilized to flash saidlow pressure steam and a .through the preheater over the boiler demand aconduit conducting water from said accumulator to said primary boiler, apump in said last mentioned conduit,-a consumer,

and a conduit conducting steam from said accumulator to said consumer.

3. In a steam plant, a primary boiler generating steam at substantiallyconstant pressure, a igh pressure consumer, .means to conduct steam fromsaid primary boiler to said high pressure consumer, an accumulator,means .to force water from said accumulator to said primary -boiler,-apreheater, a conduit'conducting water fromsaid preheater to'saidaccumulator, a' valve in the last-mentioned conduit operating tomaintain a higher pressure in said preheater than in said accumulator, alow pressure consumer, and a conduit leading steam from said accumulatorto said low pressure consumer thus allowing a drop of pressure betweensaid preheater and said accumulator and in said accumulator to flashsteam for low pressure consumption in the plant.

4. In a steam plant, a primary boiler gen-iadapted to flash steam and tooperate under '\"arying'pressurcs, a preheater, a conduit leadingwaterfrom said preheater to said accumulator, means to force water from saidaccumulator to said pr mary boiler, a low pressure consumer, means tolead steam from said accumulator to said low pressure mm sumer, andmeans to mamtam'the pressure in the p'reheater constant.

5. In a steam plant, a primary boiler generating steam at substantiallyconstant pressure, an accumulator adapted to flash steam and to operateunder varying pressures, a. preheater, a conduit leading water fromsaid.

prehea-ter to said accumulator, means to force water from saidaccumulator to said primary boiler, a consumer, means to lead steam fromsaid accumulator to said consumer, means to maintain the pressure in thepreheater constant, a second preheater, conduits connecting saidsecondjpreheater with said accumulator. and means to main}: tamcirculation. in said second preheater,

accumulator andconduits connected therebetween, I

6. In a steam plant, a primary boiler generating steam at substantiallyconstant pressure, a high pressure steam consumer, means to conductsteam from said primary boiler to said steam consumer, an accumulatoradapted to flash steam and to operate under varying pressures, apreheater, means to supply Water to said preheater a conduit leadingwater from said preheater to said accumulator, means to force water fromsaid accumulator to said primary boiler, a low pressure consumer, meansto. lead steam from said accumulator to said low pressure consumer,means to maintain the pressure in the preheater constant, a steamconduit extending between said primary boiler and primary boiler, 21.consumer, a conduit lead v ing steam from said accumulator to saidconsumer, a second preheater in said flue, and means to causecirculation through said accumulator and said second preheater.

' 8. Ina steam plant, a primary boiler, an accumulatofla preheater, aconduit conducting water from said preheaterto said accumulator, and aconduit conducting water from said accumulator to said boiler.

9. The method-of operating a steam plant which comprises preheating feedwater, discharging the preheated water into an'accu mulator, flashingsteam from said water, utilizing the steam thus-generated for lowpressure consumption in the plant, and

pumping the remainder of the water to a primary boiler for thegeneration of high pressure steam.

10. The method of operatinga steam plantwhich comprises preheating feedWater by means of flue gases, dischargingthe preheated water into anaccumulator, flashing steam from said water, utilizing the steam thusgenerated for low pressure consumption in the plant, and pumping theremainder of the Water to a primary boiler for the generation of highpressure steam,

11'. The method of operating a steam plant which comprises preheatingfeed Water at constant pressure, discharging the preheated water into anaccumulator and storing the same therein, flashing steam from saidwater, utilizing the steam thus generated for low pressure consumptionin the plant, and'pumping the remainder of the water to a primary boilerfor the generation of high pressure steam at a rate'dif ferent from andindependent'of the rate of discharge of Water into the accumulator.

12. The method of '-operating a steam plant which comprises preheatingfeed Water, discharging the preheated water into an accumulator,flashing steam from said water, utilizing the steam thus generated forlow pressure consumption in the plant, pumping water from theaccumulator to a boiler for generation of high pressure steam andstoring surplus steam generated'in the accumulator. 1

13.,The' method of generating steam in two stages which comprisesconducting water ina path, delivering heat to the water,

causing a generationof low pressure steam from part of the-water,utilizing the steam for low pressure consumption, raising the pressureof the water which has not been converted into steam and applying heatto this water at higher pressure vto generate high pressure steamtherefrom.

14. Themethod of generating steam in two stages which comprises heatinga quantity of water, lowering the pressure in the 1 water and causing apartial generation of steam therefrom by drop in pressure, conductingthe steamgenerated to .use in low pressure consumers, raislng thepressure of v the remaining water applying heat therego and generatinghig pressure steamthererom.

15. The method of generating steam in two stages which comprisesconducting'ww ter through a feed water preheater, apply ing heat to thepreheater, flashing a part of the water into steam, leading the lowpressure consumers, raising the pressure of the remaining water, andgenerating high pressure steam therefrom by the application of eat.

16. In a steam plant, a primary boiler, an accumulator, a consumer, apreheater, a conduit conducting water from'said preheater to saidaccumulator, a conduit conducting water from said accumulator to saidboiler, a conduit leading steam irom said accumulator to said consumer,and additional means to supply'heat to the accumulator.

- In testimony whereof I ailix my signature.

EMIL JossE.

Certificate of- Correction.

It is hereby certified that in Letters Paten upon the application ofEmil Jesse, of Be Steam Generation in Two Sta es,

requiring correction as follows: age 3, line 105, claim 15, before theword 10W insert the words low pressure steam til/us generated to," andthat the said Letters Patent should be read with this corre rlin,Germany, for an improvement in v ction therein that the same may convform to the record of the case in the Patent Oflice.

. Signed and sealed this 8th day of June, A. D. 1926.

[SEAL] M. J. MOORE, I Acting Commissioner of Patents.

t No. 1,583,557, granted May 4, 1926,

an error appears in the printed specification

